1. Field of the Invention
The present invention relates to a system for online monitoring powder-based 3D printing processes and method thereof, in particular to a system for online monitoring through acquiring a contour of pattern in real time before and after printing and confirming a result of layer by layer comparing with a 3D model of computer and method thereof.
2. Description of the Related Art
With the rapid development of the printing technology associated with computer, 3D printing technology has started its evolution in the computer industry, and the technology of the powder-based 3D printing is one of the most popular in the 3D printing technology.
The technology of the powder-based 3D printing includes finishing the drawing of the 3D models which are prepared to be printed first on the computer, then performing layer by layer powder bed printing on a flat plate by a powder-based 3D printing device according to the 3D models, and finally generating a 3D object which is same as the 3D models on the computer. The method for the so-called layer by layer powder bed printing is to preset the printing settings corresponding to each layer of pattern in the 3D models of computer. Then, the powder-based 3D printing device performs the printing of the layer according to the printing settings of each layer. In general, the paving of the powder is performed first. Glue is then applied on the powder layer. The powder applied with glue will be gradually solidified to generate the desired contour of pattern. The final desired 3D object may be generated via powder bed printing layer by layer.
Theoretically, the powder paved by the powder-based 3D printing device should be flat and the glue applied should be even. However, because of the low precision of the elements and the components of the powder-based 3D printing device and the poor application technology, the paving of the powder readily causes roughness and the application of glue readily causes unevenness. This situation will also lead to the problem of the contour defects appearing on the contour of pattern (i.e. irregularities appearing on the contour), which results in the differences between the final print out of the 3D object and the 3D models on the computer. The U.S. Pat. No. 8,847,953, is a technical scheme which proposes how to perform the comparison of the differences between the 3D object and the 3D models on the computer after the printing is completed.
However, the powder-based 3D printing always takes considerable time, and the cost of the materials used such as powder and glue powder is not low. Thus, if the comparison of the differences is performed after the printing process is completed, much time will be wasted and a lot of printing resources will be consumed. Therefore, a monitoring mechanism with real-time performance for powder-based 3D printing is essential indeed.